Children who are regularly slapped or pushed by their parents or caregivers face a higher risk of developing mental illness as adults, Canadian researchers have found.

The study is thought to be the first to suggest that mental problems such as anxiety disorders, depression and substance abuse problems, can develop in kids who are not abused but who are regularly physically punished at home.

For this study, Tracie Afifi from the department of community health sciences at the University of Manitoba, led a team who tried to narrow in on a very specific kind of physical discipline: not a once-in-a while spank, but a consistent pattern of hitting and shoving.

But they excluded those who faced severe maltreatment, such as heavy physical abuse, sexual abuse, neglect, or emotional abuse. Research has already shown that those who experience those types of abuse are at higher risks of psychological problems.

The researchers looked at a large U.S. survey performed between 2004 and 2005 and narrowed in on the question in which respondents were asked “As a child how often were you ever pushed, grabbed, shoved, slapped or hit by your parents or any adult living in your house?”

Respondents who answered “sometimes” or “often” were considered as having experienced harsh physical punishment.

Around 1,200 or so said they had experienced such punishment. The researchers then compared them to the nearly 20,000 others who reported they rarely or never experienced such punishment.

They found that those who had experienced physical punishment were more likely to encounter mental health issues later in life:

  • Their risk of depression was 1.4 times greater
  • Their risk of anxiety was also 1.4 times greater
  • Their risk of alcohol abuse was 1.6 times higher
  • Their risk of drug abuse was 1.5 times higher

The researchers adjusted their findings to account for those factors that might have affected the results. For example, if a respondent’s parents were hospitalized for mental illness, that could have affected their risk as well.

The study authors say this study, which appears in the journal Pediatrics, adds to the growing literature about the adverse outcomes associated with exposure to physical punishment.

“The American Academy of Pediatrics strongly opposes striking a child for any reason, and the Canadian Pediatric Society recommends that physicians strongly discourage the use of physical punishment,” the authors note.

They say that both groups should consider more explicit position statements that state that smacking, slapping or spanking should not be used with children of any age.